Method of and apparatus for making gummed paper



April 10, 1928. 1,665,611

W. H. SMITH ET AL METHOD OF AND APPARATUS FOR MAKING GUMMED PAPER FiledJan.26. 1926 W m INVENTQRS ,ZZWM? r ATTORNEY Patented Apr. 10, 1928.

UNITED STATES PATENT orrlca.

WILLIAH HENRY SMITH. AND ALBERT srnwanr waas'rnn, or OTTAWA, oN'rABIo,CANADA, ASSIGNORS 'ro AMERICAN BANK NOTE COMPANY, or NEW YORK, N. 1., A

CORPORATION OF NEW YORK.

METHOD OF AND APPARATUS FOR MAKING GUMMED PAPER.

1 Application filed January as, 1926. Serial .No. 83,781.

Our invention relates to a method of making gummed paper and anapparatus used in the practice of said method, and more parthe solventor other vehicle for the gum or other adhesive being by adrying process,which causes the hardenlng or crystallization of the gum or otheradhesive material.

The contractionof the material of said body or its shrinkage during thehardening or crystallization results in the development of stresses atone surface of the paper which causes the paper to curl.

While for some purposes the curling of gunnned paper is notobjectionable, when a strip or web, or-large sheets of such paper are tobe printed upon, the paper, In order to permit its being properly fed inrelation to the printing couple, and to permit the making of a cleanimpression, should be flat, in order to secure quality in the' printedproduct. In other words, non-curling paper is required in the bettergrades of printing when the impressions are made upon previously gummedpa er. v- I In work of this kind, it has heretofore been the practice,particularly when printing on a paper web, to make the impression firstand gum the opposite side of the sheet following the making of theimpression. While this practice obviates those difficulties during themaking of an impression resulting from the use of curled gummed paper,in the subsequent cutting or perforatln of such printed and gummedpaper, difiicu ties are encountered by reason of the tendency of thepaper to curl, these difiiculties resulting in a slowing down of suchoperations and the frequent spoilage of work. It has heretofore been thepractice in order to avoid the above difliculties, to use certainmaterials such as red oil in the solution to weaken the bond betweenadjacent crystals of the body of the adhesive formed by the eliminationof the vehicle from the adhesivt and thus lessen the stresses due to thecon-1y tract ion of this material to an extent tomaterially lessen, ifnot to entirely avoid, 'dis- 3' tortion of the paper or its'curling lt'has;

also been the practice to mechanically break down the bridge of crystalsafter the vehicle has been removed from the adhesive, thus relieving thepaper from -the stresses and permitting it to flatten out. a

The addition of oil. to the adhesive tend to weaken its bonding proel-ties when moisture is restored to the adiesive for making it tacky,and the mechanical. breakage'of the crystalline structurefofjthe driedadhesive'not only involvesa re-handling'of the paper, but-vwastage ofitheadhesive during the breaking operation. ..;Furthermore..a

thicker coating of adhesive must 'be' used I to compensate for lossesresulting from the flocking of the adhesive from the paper-dur ing thisbreaking operation. v

By the process of our inventlon, we-are enabled to produce anon-curling'ystrip or' web by a rapid and continuous operation whilesecuring an effective substantially continuous coating of adhesive upon.one surface thereof, which adhesive contains no oil will impair thebonding properties of, the adhesive, or interfere with the quickabsorption of moisture thereby when it is'desired" those conditionswhich result in the distortion or curling of the paper rather thanusingcorrective ingredients in the adhesive, or destroying theconditions developing such stresses after the aper has once beendistorted or curled. is permits the adhesive to be. appliedina thincoating to the paper, ensures the entire quantity of adhesive'used beingretained in this coating, and permits the economical production of thepaper from the st-andpoints of time and labor whilesecuring anon-curling oduct. While the coating of adhesive is being applied toithepaper, and the vehicle orsolvent removed therefrom, the strip or web ofpa r is sub jected -'to a continuing lon 'tudmal-stress which assists inpreventing edis tortionor the vehicle or other moisture-repellentmaterial which l I curling thereofduring the drying out process to whichthe adhesive coating is subjected. The time interval in the coatln ofthe paper is very short, and thefinis ed gummed product is suflicientlyflexible, and

- the gum thereon issufiiciently dry, to permit although when applylngthe gum t sheets the results will not be as good as when applying it toa strip or web, since the longitudinal stresses in the sheet can not beadvantageously secured and the evaporation of the vehicle of theadhesive is more difficult and less rapid.

The invention consists primarily in the method of making gummed paperconsisting in applying a solution containing adhesive material and avehicle to the surface of paper, subjecting the same to a lowtemperature and then to a relatively higher temperature, whereby thevehicle will be removed from the surface of the solution inwardlythereof progressively to cause a progressive crystallization of theadhesive material and the readjustment of the adhesive material duringits crystallization and avoiding those stresses result-ingin curling ofthe paper, and in an apparatus for carrying on said process; all ashereinafter set forth and described, and more particularly pointed outin the claims hereto appended.

In the accompanying drawing, we have illustrated an apparatusparticularly adapted for use in the rapid gummingof a paper strip orweb.

In the production of gummed paper by the method of our invention, weapply to one surface of the paper a solution containing an adhesivematerial and a vehicle, this solution being spread in a thin filmthroughout that portion of the paperwhich is to be gummed. The adhesivematerial usedin this solution ma vary widely as may the solventconstituting the vehicle, our invention not depending in any way uponthe particular material .or solvent since with all adhesives thehardening thereof results from a drying out process, or the elimination,as by evaporation of the solvent or vehicle. This hardening actionresults in a crystallization of the adhesive material and the method ofour invention resides in so controlling the speed of elimination, orevaporation, of the vehicle as to secure the complete hardening thereofwithout development of stresses resulting from the contraction of theadhesive as a mass, or its shrinkage as 9.

mass, to an extent to cause curling of the paper, due to the paper,particularly when dry, havin substantially no shrinkage or a lowershrmkage than the adhesive.

After the thin film of adhesive solution is applied to the paper, it issubjected to 'a low temperature as by passing 1t through a zonemaintained at the desired temperature which may be ordinary factorytemperatures or about to 90 F. Any particular temperature in this zoneis not required so long as it is sufliciently low to cause a slowevaporation of the vehicle or. solvent and limit this action to adjacentthe exposed surface of the film of adhesive solution.

Immediately following the subjection of the coated paper to this lowtemperature, it is subjected to a relatively higher temperature to causethe elimination or evaporation of the vehicle, or solvent, within thesurface of the film of adhesive solution, the paper finally beingsubjected to a still higher temperature in order to ensure thecompletion of the elimination, or evaporation, of

the solvent throughout the entire mass of the adhesive and the completedrying of the exposed surface of the adhesive.

The best results can be secured by holding the paper substantial] flator taut while it is being subjected to t ese different temperatures, andsubjecting it to'a bendlng action before it is subjected to the highertemperature, or following hardening, or partial hardening, bycrystallization, of the adhesive material adjacent the surface of thefilm and before the material between this surface and the paper has beenthus hardto break or weaken the bond between adjacent crystals of theadhesive material and thus cause a readjustment of the solution while itis still in a'viscous or semi-plastic state, and a readjustment of thismaterial of the solution in a manner to ,-.compensate for its shrinkage,or-contraction, as a mass and prevent the distortion or curling. of thepaper. i

The portionof the adhesive solution which will be last to harden orcrystallize will be that which is adhered, or'an'ehored, to the paperitself so that. the subsequent hardening of this portion of the adhesiveby reason of the more or less separated por-- tions thereof entering thefibers of the paper, will have no effect of distorting the paper. 'Whilethe method of our invention inthe higher temperature zone, and being suhjectcd to the final high temperature for between three to live seconds.These time intervals, however, are not inflexible, and will varyaccording to the adhesive material in the solution and the or solvent.

Satisfactory results can be secured with a temperature in the heatedzone ranging from about 125 to 200.the highertemperature being utilizedfor the final stage,at which point the adhesives will have hadsubstantially all of the vehicle or solvent removed,

so that the higher temperatures used will cause no reactions which willdestroy the adhesive properties of the .gummed surface when moisture isapplied thereto, when it .is desired to use the article made from thepaper. The lower range or these higher temperatures represents thenormal drop in the temperature of the air circulating in the heatedzone, the first heated zon'ebemg characterized by thepresence ofagraduated tcmjperatnre which becomes progressively higher with alowering of the uautity of the vehicle or solvent 'in the 'ad iesi ve,or with the progressive elimination or evaporation of such moisture.

So far as we have been able' to determine, thepractice of the-methodof'our invention is characterized by the following conditions.

As the paper with its coating film of adhesive solution is passingthrough the low temperaturezone, the vehicle. orsolvent of the portionof the adhesive adjacent the exposed surface thereof will rapidly beeliminated or evaporated, thus causing a hardening. or partial hardeningof the solution superficially of this film. This. action will beaccompanied by shrinkage of. the adhesive material of this portion ofthe solution, but

this shinkage will be in relation to the contiguous portions of thesolution, and hence will merely cause a readjustment of these portionsof the solution. or of the adhesive material without subjecting thepaper to any of the stresses resulting from this contraction orshrinkage. This action will'go on progressh'ely through the thickness ofthe film so that by the time the treatment in the low temperature zoneis completed, the

shrinkageor contraction of the material ofthe adhesive solution willhave progressed to quantity ot the vehicle a point where any subsequentshrinkage will be so small as to have no eflect in imparting a curl tothe paper.

At the conclusion of this stage the elimination, or evaporation, of thevehicle or solvent will not have occurred as to the whole mass of theadhesive solution, and the continuing escape of said vehicle or solventwill tend to keep the entire mass in a viscous condition. Hence abending of the paper away from the coating film, accompanied by pressureresulting from stresses applied through the paper against the objectoverwhichthe paper is bent,will have the effect of causing the readjustmentof different parts of the adhesive with relation to each other, in amanner to counteract any shrinkage or contraction which has occurredfrom the partial or complete hardening of some of the material.Consequently the subsequent rapid elimination, or evaporation, of theremain-.

ing vehicle or solvent will be accompanied by so little contraction orshinkage as to have no effect of curling the paper, particularly asduring this stage, the portion of'the fl-adhesive solution whichissubjected to contraction or shrinkage will be between that portionthereof superficially of the fihn and adjacent thereto and'ithe paper,and will meet with resistance ifrom the paper, and also from thepreviously hardened or partially hardened portion ofthe film. The

condition of theadhesive in passing from the low to the highertemperature stage 1s also such that the bending actionv accompanied bypressure will not cause crackageor flecking at the surface of theadhesive,

and may even be accompanied by a stretch' ing or attenuation ofpartially hardened portions of the film, or theseparation of adjacentparticles in a manner to' prevent the development of those stresseswhichwould curl the paper. i V

In passing through the zone of higher temperature, the vehicle orsolvent between the superficial portion of the film of adhesive and theportion thereof which has been hardened or partially hardened, will berapidly expelled from the adhesive, this portion of .the coating,however, having undoubtedly already been subjected-to a certain degreeof contractionor shrinkage, and

having been readjusted with relation to the paper and to the hardenedorpartially hard-' cued material, superficially of the film, and adjacentthereto. In fact, when passing through this stage, the drying out of thead-,

hesive solution has progressed to a point where subsequent eliminationof the remainl ing vehicle or solvent'will not result in suchcontraction or shrinkage-of the material of the coating asto apply anystresses to the paper.

The portion of the adhesive in direct contact with, and anchored to thesurface fibers of the paper, with the elimination, either complete orpartial, of the vehicle or solvent therefrom, will have the more or lesssegregated portions thereof contract or shrink in relation to the paper,and away from each other so'as not to be so bonded to adjoining crystalsof the adhesive as to have any effect in developing stresses tending todistort or curl the paper.

'Ihroughont. the method is characterized by the hardening or partialhardening of a portiop of the adhesive material resulting from theelimination or evaporation of the vehicle or solventthercfor,accompanied by contraction or shrinkage of this portion of the adhesive,this contraction or shrinkage being with relation to portions of theadhesive which are still in a viscous or semiplastic form so as not totransmit any stressesigto the paper which would result in the curlingaction. lly thus avoiding the effects of such contraction or shrinkage,the thickness of the film of adhesive solution may be restricted tosecure the desired thickness of the dried gum or other adhesive materialupon the finished product, there being no losses due to the flecking ofparticles of the material as when breaking down a completely formedbridge of the crystals. Furthermore, there will be no cracking of I thedried adhesive.

The product is gummed paper having no appreciable tendency to curl, andhaving a thin continuous film of drled adhesive thereof the possibilityof increasing the cheapness of the ingredients of the solution, and areduction in the quantity of the adhesive used to coat the paper, butalso by reason of the high speed at which paper, particularly in stripor web form, may becoated with the gum and the fact that the process maybe carried on by means of an apparatus requlr ing little or no attentionfrom the operator.

An apparatus suitable for use in the practice of said method or art isshown in the accompanying drawing. As shown, this apparatus embodiesaframe 1 provided with bearings for a reel 2 for a roll of paper'to becoated. -Adja'cent said bearings is a fountain 3 adapted to receive asupply of the adhesive, this fountain having associated therewith ar0114 suitably surfaced to pick up adhesive from the fountain and applyit to paper fed with relation thereto. Cooperating with the fountainroll 4. is a feed roll'5, a tension roll 6 being positioned between thisfeed'roll and the supply reel of the paper supply roll.

Closely adjacent the adhesive solution applying mechanism, is avertically extending housing or stack 7' open toward the bottom thereofso as to permit air to circulate freely through said housing or'stack.

The method is not only economical because The top of the stack isprovided with a hood stantial alinement with the turning roller 9,

and a second roller 11 which, for convenience of expression, Wlll betermed a breaker roller, about which the paper strip or Web passes andchanges its course from an upward to a downward run.

Mounted in the frame 1 is a rewind reel 12 co-operating with which aresqueeze rollers 13 and 14 by which the paper strip or web isfrictionally fed through the machine and rewound upon the reel 12. Oneof these rollers as 13 is driven from any source of power as the motor15. Below the stack and in substantially vertical alinement with theroller 11 is a turning roller 16, and between this roller 16 and thesqueeze roller 13 are suitable guiding and tensionin'g rollers 17, 18and 19.

Mounted upon the frame 1 below the stack 7 is a roller 20 and adjacentthe topof the stack is a second roller 21 about which an endlesstraveler-belt 22 of substantially the same width as the housing orstack, passes. The roller 21 is preferably of smaller di ameter than theroller 20. The belt 22 divides'the housing or stack 7 into two passagesor conduits, which for all practical purposes are unconnected exceptadjacent the top of the housing or stack. One of these passages,indicated at 23, permits the circulation of'air at normal factorytemperatures th'erethrough, so that it may properly be termed a coldail-conduit. The other of these passages, indicated at 24, has heatedair delivered thereto adjacent the bottom thereof from any desiredsource of heat, and

"hence may appropriately be termed a hot air conduit. In the upward runof the paper or web in the housing or stack 7, it passes through thecold, air conduit 23 andin its downward run, it passes through thehotair conduit 24 and toward the point'where the heated air is deliveredto the stack.

In the form of the invention shown, the source for the heated air is anelectrical resistance device 25 supported from the frame 1 of themachine adjacent the bottom of the housing or stack 7, and also adjacentthe roller 20, so that air in passing between said housing and saidsource of heat will attain the temperature required in the practice ofthe method of our invention.

The feed roll 5 and the roller 20 are driven in any desired manner so asto secure a feeding of the paper strip or web from the supply roll, withsubstantially the same speed as that of the travel of the belt 22. Thespeed of the roller 13 is also such as to ensure the travel of the paperat substantially the same speed as that of said belt 22, while keepingthe strip or web taut.

As shown. in the drawing, the roller -5 is driven from an electric motor26, and is connected by a chain and pulley mechanism 27 with the roller20 so as to secure the desired relative speeds of said rollers 5 and 20to secure the above results. The paper strip or web is indicated at 28.

In an apparatus as herein described, the paper strip or web 28 is ledfrom the roll upon the reel 2 under the tension roller 6, between therollers 4 and 5, about the turning roller 9, over the guide roller 10,about the breaking roller 11, downwardly toward and about therollers'lfi, 17, 18 and 19, between the squeeze rollers 13 and 14, andupon the rewind'reel 12. When the paper is thus threaded through themachine, it will be noted that the upward reach thereof is within thecold air conduit 23 of the housing orstack 7 and is positioned away fromthe upward reach of the belt 22, and that there is a progressivelyincreasing capacity of this conduit toward the top thereof by reason ofthe inclination of the belt 22; and that the downward reach of the paperstrip or web is within the hot air conduit 24. Toward the end of thisdownward reach, the gummed surface of the paper is resented towards theelectrical resistance evice 25.

With this construction, as the paper stripv or web 28 passes between therollers 4 and 5,. one surface thereof has a thin film of ad- .hesivesolution from the fountain 3 applied thereto, the turning roller 9having a spreading action upon thisfilm, although its main purpose is tochange the direction of travel of the paper or web to an upward coursethrough the cold air conduit 23. As the paperpasses through this coldair conduit, the gummed surface thereof is present ed away from the belt22 where it will be subjected to the action of the air flowing upwardlythrough the'conduit 23. The ungummed surface of the paper will be heldaway from the belt 22 by the upper guide. roller 10. This upward reachof the roller is approximately 30 feet long, although this lengthisstated as merely one at which satis-' factory results have beenattained, and not as being essential.

After passing the guide roller -10, the strip or web 28 passes about theroller l1? where .it receives a fairly sharp bend, and is subjected-topressure resulting from the drag upon the strip-by the squeeze rollers13 and 14, and passes downwardly through the hot ain conduit 24.- Itwill be observed that during\the part of this travel adjacent the to ofthehousing or stack 7, the hot air wi l have lost some of its heatthrough radiation, and that hence there will be agradually increasingtemperature from this point to -a point adjacent the heater 25 where thetemperature will be at its highest. Hence during the downward travel ofthe paper strip or web 28 through the hot air conduit, it will besubjected to a progressively higher temperature, and will, while passingthe heater 25, be subjected to a sub stantially uniform hightemperature.

While the strip or web 28 is passing upwardly through the conduit 23,the cold air will act superficially of the film of adhesive solutionupon the paper strip or web, the rapid circulation of cold air ensuringa condtinuous supply of fresh air and a change of this alr withsufficient rapidity to carry off the vehicle or solvent for theadhesivc'material as it evaporates from the solution. This action willbe gradual, and will have the effect of limiting the initial hardeningaction to adjacent" the surface of the film of the solution.

In passing about the breaking roller 11,

hardened portions thereof, to compensate for any shrinkage orcontraction of the portion thereof which has been hardened or partiallyhardened.

During the downward run of the paper strip or web 28 through the hot airconduit- 24, the coated surface of the paper will be presented away fromthe belt 22 and the igher temperature of the air circulating throughthis conduit-will cause a rapid elimination, or evaporation, of thevehicle or solvent remaining in the film of thesolutiom Throughout atleasta portion of the travel of the paper strip or web through thisconduit 24, the surface of the adhesive film will be tacky, but thepassage thereof adjacent the heater 25 will have the eifect of a finalrapid drying action upon this coating, so that after theistrip or web 28leaves its proximity to the heater, the adhesive will be suflicientlydry and hard to permit it to 'pass the various guide and tensioningrollers 16, 17, 18 and 19 and thexsqueeze rollers 13 and 14, and berewound upon the reel 12 without any likelihood of the gummed surface ofthe paper strip or web adhering to these rollers or to the strippreviously wound upon said reel.

'We have found an a-pparatusasherein described, to give highlysatisfactory re-; salts, and to produce a gummed paper which has notendency to curl, so that gummed paper may be Withdrawn from the rollupon said reel and passed through a printing machine, and have a cleansharp impression applied to every portion thereof.

, claim as new and desire to have protected by Letters Patent, is

1. The herein described method of making gummed paper consisting inapplying a solution containing adhesive material and a vehicle to oneface only of paper, subjecting the same toa low temperature and then toa relatively higher temperature, whereby the vehicle will be removedfrom the surface of the solution inwardly thereof progressively to causea progressive crystallization of the adhesive material and there--adjustment of the adhesive material during its crystallization andavoiding those stresses resulting in curling of the paper.

2. The herein described method of making gummed paper consisting inapplyin a solution containing adhesive material an a vehicle to one faceonly of paper, subjecting the same to a low temperature, then to arelatively higher temperature, whereby the vehicle will be removed fromthe surface of the solution inwardly thereof progressively to cause aprogressive crystallization of the adhesive material and thereadjustment of the adhesive material during its crystallization andavoiding those stresses resulting in curling of the paper, andthereafter subjecting the same for a short interval to a relativelyhigher temperature to ensure a thorough drying out of the adhesive atthe surface thereof.

3. The herein described method of making gummed paper consisting inapplying a solution containing adhesive material and a vehicle to oneface only of the paper, circulating air' at a low temperature adjacentsaid surface, and thereafter circulatingair at a relatively highertemperature adjacent said surface, whereby the vehicle will be removed.from the surface of the solution inwardly thereof progressively'to causea progressivecrystallization of the adhesive material. and thereadjustment of the adhesive material during its crystallization andavoiding those istresses resulting in curling of the paper. The hereindescrilgedmethod of making gummed paper consisting in applying asolution containing adhesive material and a vehicle to one face only ofthe paper, circulating air at a low temperature adjacent said surface,thereafter circulating air at a relatively higher temperature adjacentsaid surface, whereby the vehicle will be removed from the surface ofthe solution inwardly thereof progressively to cause a progressivecrystallization of the adhesive material and the adjustment of theadhesive material during its crystallization and avoiding those stressesresulting in curling of the paper, and thereafter subjecting the samefor a short interval to a relatively higher temperature to ensure athorough drying out of the adhesive at the surface thereof.

5. The herein described method of making gummed paper consisting inapplying and spreading a solution containing adhesive material and avehicle to one face only of a strip or web of paper, passing said stripor'web upwardly wlnle subjecting it to circulating air at lowten'lperature, and thereafter passing said web downwardly whilesubjecting it to an upward circulating airat a relatively highertemperature, whereby the vehicle will be removed from the surface of thesolution inwardly thereof progressively to cause a progressivecrystallization of the adhesive material and ,the readjustment of theadhesive material during its crystallization and avoiding those stressesresulting in curling of the paper.

6. The herein described method of making gummed paper consisting inapplying and spreading a solution containing adhesive material and avehicle to one face only of a strip or web of paper, passing said stripor web upwardlywhile subjecting it to circulating air at lowtemperature, thereafter passing said web downwardly while subjecting itto upwardly circulating air at a relatively higher temperature, wherebythe vehicle will be removed from the surgressively to cause aprogressive crystallization'of the adhesive material and thereadjustment of the adhesive material'during its crystallization andavoiding those stresses resultin in curling of the paper, and thereaftersu jecting the same for a short interval to a relatively highertemperature to ensure a thorough drying out of the adhesive at thesurface thereof. 7. The herein described method of making gummed paperconsisting in applying a solution containing adhesive material and avehicle to one face only oflpaper, subjecting the, same to a. lowtemperature, giving a sharp bend to the paper in the direction away fromthe surface having the adhesive thereon and simultaneously applyingstresses to the paper on opposite. sides of the point where it is bent,and thereafter to a relaof a strip or web of paper, passing said stripor web upwardly while subjecting it to circulating air at lowtemperature, giving a sharp bend to the paper in the direction away fromthe surface having the adhesive thereon and simultaneously applyingstresses to the paper on opposite sides of the point where it is bent,and thereafter passing said web downwardly while subjecting it toupwardly circulating air at a relatively higher temperature, whereby thevehicle will be removed from the surface of the solution inwardlythereof progressively to cause a progressive crystallization of theadhesive ma terial and the readjustment of the adhesive material duringits crystallization and avoid ing those stresses resulting in curling ofthe paper.

, 9. The herein described method of making guinnied paper consisting inapplying a so lution containing adhesive material and a vehicle to oneface only of paper, subjecting the same to a low temperature, giving asharp bend to the paper in the direction away from the surface havingthe adhesive thereon and simultaneously applying stresses to the paperon opposite sides of'the point where it is bent, thereafter subjectingit to a relatively higher temperature, whereby the vehicle will beremoved from the surface of the solution inwardly thereof progressivelyto causea progressive crystallization of the adhesive material and theread-- justment of the adhesive material during its crystallization andavoiding those stresses .resulting in curling of th paper, andthereafter subjectin the sam for a short interval to a relatively highertemperature to ensure a thorough drying out of the adhesive at thesurface thereof.

10. The herein described method of making gummed paper consisting inapplying .and spreading a solution containing adhesive material andavehicle to one face only of a strip or web of paper, passing said stripof web upwardly while subjecting it to circulatin' air at lowtemperature, giving a sharp fiend to the paper in the directioiiawayfrom the surface having the adhesive thereon and simultaneously applyingstresses to the paper onv opposite sides of the point where it is bent,thereafter passing said Web'downwardly while subjecting it to upwardlycirculating air at a relatively hlglier temperature, whereby the vehiclewill be removed from the surface of the solution.

inwardly thereof progressively to cause a sive material during itscrystallization and avoiding those stresses resulting in curling of thepaper, and thereafter subjecting the same for a short interval to arelatively higher temperature to ensure a thorough drying out of theadhesive at the surface thereof.

1.1. The herein described method of making guinined paper consisting inapplying a solution containing adhesive material and a vehicle to oneface only of paper, subjecting-the same to a low temperature and then toa relatively higher, and a gradually iiicreasing, temperature, wherebythe vehicle will be removed from the surface of the soll1- tioiiinwardly thereof progressively to cause a progressive crystallization ofthe adhesive material and the readjustment of the adhesive materialduring its crystallization and avoiding those stresses resulting incurling lization of the adhesive material and the readjustment of theadhesive material during its crystallization and avoiding those stressesresulting in curling of the paper, and there after subjecting the samefor a short interval to a relatively higher temperature to ensure athorough drying out of the adhesive at the surface thereof.

13. The herein described method of making gummed paper. consisting inapplying and spreading a solution containing adhesive material and avehicle to one face only of a strip or web of paper, passing-said stripor web upwardly while subjecting it to circulating air at low tein'ie'rature. thereafter passing said web downwardly while sub ecting itto upwardly circulating air at a relatively higher, and it graduallyincreasing, temperature, whereby the vehicle will be removed from thesurface of the solution inwardly thereof progressively to cause aprogressive crystallization of the adhesive material and thereadjustment of the adhesive material during its crystallization andavoiding those stresses 'esultin in curling of the paper, and thereaftersubjecting the same for a short interval to a relatively highertemperature to ensure a thorough drying out away from the surface havingthe adhesive thereon and simultaneously applying stresses to the paperon opposite sides of the point where it is bent, thereafter subjectingit to a relatively higher, and a gradually increas ing, temperature,whereby the vehicle will be removed from the surface of the solutioninwardly thereof progressively to cause a progressive crystallization ofthe adhesive .material and the readjustment of the adhesive materialduring its crystallization and avoiding those stresses resulting incurling of the paper, and thereafter subjecting the same for a shortinterval to a relatively higher temperature to ensure a thorough dryingout of the adhesive at the surface whereby thereof.

15. An apparatus for making gummed paper embodying therein meanssupporting a roll of'paper to be coated, a fountain for a solution ofadhesive material, a fountain roll, a feeding roll co-operatingtherewith, and adapted to apply the adhesiveto one surface only of thepaper to be coated, a stack open at the bottom and at the top thereof,means dividing said stack into two substantially vertical passages,means for guiding the coated paper strip or web in an upward run throughone of said passages, and in a downward run through the other of said,passages, means whereby the temperature of the air passing through thelast named of said passages is heated, a rewind reel, guiding meansintermediate said last named means and said rewind reel, and

'means drawing the paper from said supp] reel and winding it upon saidrewind ree, said paper is subjected to continu ous longitudinalstresses.

c 16. An apparatus for making gummed paper embodying therein meanssupporting a roll of paper ,to be coated, a fountain for a solution ofadhesive material, a fountain roll, a feeding roll co-operatingtherewith and adapted to apply the adhesive to one surface only'pf thepaper to be coated, a

stack open at the bottom and at the top thereof, means dividing saidstack into'two substantially Vertical passages, means for guiding thecoated paper strip or web in 'an upward run through one of saidpassages,

abreaker roller adjacent the top of .the means dividing said stack, about ,whichthe paper strip or web passes int'o downward run through theother of said passages, means whereby the temperature of the air passingthrough the last named of said passages isheated, a rewind reel, guidingmeans "intermediate said last named means and said roll, a feedingrollco-operating therewith and adapted to apply the adhesive to one surfaceonly of the paper to be coated, a stack open at the bottom and at thetop thereof, rollers adjacent the top and the bottom of saidstack, anendless belt passing about said rollers whereb said stack is dividedinto two substant1ally Vertical passages, means for guiding the coatedpaper strip or web in an upward run through one ofsaid passages, and ina downward run through the other. of said passages, means wherebythe-temperature of the air passing through the last named of saidpassages is heated, a rewind reel, guiding means intermediate said lastnamed means and said rewind reel, and means drawing the paper from saidsupply reel and winding it upon said rewind reel, whereby said paper issubjected to continuous longitudinal stresses.

18. An apparatus for making gummed paper embodying therein meanssupporting a roll of paper to be coated, a fountain for a solution ofadhesive material, a fountain roll, a feeding roll co-operatingtherewith, a

stack open at the bottom and at the top,

sages, means for guiding the coated paper strip or web in an upward runthrough one of said passages, a breaker roller adjacent the upper ofsaid rollers about which said belt passes, about which the paper stripor web passes into a downward run through the other of said passages,means whereby the temperature of the, air passing through the last namedof said passages is heated, a rewind reel, guiding means intermediatesaid last named means and said'rewind reel, and means drawing the paperfrom said supply reel and winding it upon said rewind reel, whereby saidpaper is subjected to continuous longitudinal stresses.

19. An apparatus fornnaking gummed paper embodying therein meanssupporting a roll of paper to be coated, a fountain for a solution ofadhesive m aterial',;-; afountain roll, a feeding-roll cooperat-ingfgthere yith, a

stack open at the bottom and at the top thereof,rollers adjacent the topand the bottom of said stack an endless belt passing about said roller:whereby said stack is sages, means for guiding the coated paper strip orweb in an ugward run through one of said passages, a reaker rolleradjacent the upper of said rollers about which said belt passes, aboutwhich the aper strip or web passes into a downward run throu h the otherof said passages, means where f the temperature of the air passingthrong 1 the last named of said passages is heated, a rewind reel,guiding means intermediate said last named means and said rewind reel,squeeze rollers engaging the web adjacent said rewind ree1 and acting uon the web wound upon sald reel, where y said through said stack andsubjected tdcohtinuons longitudinal stresses, and means wherebysaidfeeding roll, and said fountain roll, and said squeeze rollers arerespectively rotated at the same peripheral speed and said belt isdrivenat substantially the same speed. as that of the paper strip or web. 4

paper is drawn Inwitness whereof we have hereunto ,af-

fixed our signatures ary, 1926. v

WILLIAM HENRY SMITH. I ALBERT a. STEWART \WEBSTER.

this 19th day of J anu-

